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Kuroki Kaze
Asked: 2010-07-22 04:11:38 +0800 CST

Stdout/stderr redirects in start-stop-daemon

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I'm trying to write init config that will redirect output of my daemon to two files (for stdout and stderr). The problem is, it's not working. I'm reading this right now.

So, I've done this shell script to test this approach. And it doesnt' work:

PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="Seed kurokikaze starter"
#NAME=node
DAEMON="/etc/node-version/0.1.99/bin/node"
DAEMON_ARGS="/etc/seed/kurokikaze/server.js"
DAEMON_DIR="/etc/seed/kurokikaze"

APPLOG_FILE="/var/log/seed/kurokikaze"
ERRLOG_FILE="/var/log/seed/kurokikaze-err"

PIDFILE="/var/run/seeds/kurokikaze.pid"
SCRIPTNAME="/etc/seed-init/kurokikaze"

NCMD="exec $DAEMON $DAEMON_ARGS 1>>$APPLOG_FILE 2>>$ERRLOG_FILE"

start-stop-daemon -Sbmv --pidfile $PIDFILE --chdir ${DAEMON_DIR} --exec $DAEMON --startas /bin/sh -- $NCMD

But if you start this without wrapping daemon in separate shell, it works as intended (just without stderr/stdout redirects):

start-stop-daemon -Sbmv --pidfile $PIDFILE --chdir ${DAEMON_DIR} --exec $DAEMON -- ${DAEMON_ARGS}

The question is: why first script doesn't work? System is Debian Lenny, start-stop-daemon version is 1.14.29

debian bash

3 Answers

  1. Best Answer

    Because of the order of expansion, you can't pass redirections in variables. Redirection is evaluated before word splitting.

    See BashFAQ/050, Shell Expansions and Redirections.

    • 4

  2. Your line in the script is:

    start-stop-daemon -Sbmv --pidfile $PIDFILE --chdir ${DAEMON_DIR} --exec $DAEMON --startas /bin/sh -- $NCMD

    So you are basically saying to exec $DAEMON using $NCMD as args. Try to change $NCMD to 

    "$DAEMON_ARGS 1>>$APPLOG_FILE 2>>$ERRLOG_FILE"

    and see if it works.

    If not, you will have to change your software to redirect stdout and stderr to files (maybe it already has a logging option). You can also write a wrapper script just to do the redirection but that is a little on the ugly side.

    • 1

  3. Another way for that streams redirection using of nohup like:

    nohup ./bin/servicemix ./conf/servicemix.xml > log/nohup.log 2>&1 &
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